Objectives To investigate the association between increased visceral adiposity and ovarian dysfuntion in pre-natally androgenized female rhesus monkeys, as part of a study investigating the etiology of polycystic ovarian syndrome (PCOS). ABSTRACT:Increased deposition of visceral fat in the abdomen may contribute towards the development of insulin resistance and hyperinsulinemia. In adult female rhesus monkeys, androgenized prenatally, hyperinsulinemia may be the major cause of anovulation in a manner similar to that found in the infertility and health-risk condition of polycystic ovarian syndrome(PCOS) in women. Consequently, an investigation was initiated to determine whether adiposity distribution differed between adult female rhesus monkeys, androgenized prenatally(n=30) and a group of similarly aged and sized controls(n=25). Regular estimation of serum progesterone concentrations determined ovulatory function over a 3-month period. Combined somatometric, dual-energy x-ray absorptiometry and computed tomography measurements are being taken. The completed results from this study will quantify, in detail, body composition and adiposity and will permit us to link, for the first time, specific differential fat distribution with anovulation in our investigation of a non-human primate model for PCOS in women. Key words infertility, anovulation, adiposity, polycystic ovarian syndrome, computed tomography, DEXA.